8 replies to this topic

[trubertq]

Morning all,

Can anyone suggest how best listeria can be controlled in a raw product. The product is Queen scallops and they are being blanched ( to open the shells) and IQF frozen.

The limit required by customers is absence.

The occurrence is intermittent which makes it very difficult to determine the source, but then again, the product is not being cooked so I suppose the presence of listeria is hardly surprising. Still we have to do something to try and control it.

[trubertq]

hmmm, my thoughts exactly..... I think we're doing a King Canute ......

[Tony-C]

Firstly please clarify if the Listeria is present in the incoming product

Regards,

Tony

[trubertq]

Hi Tony,

So far it has not been detected in the incoming product, but that is not to say it isn't there, there is only so much sampling that can be done before it gets into the realms of ridiculous.

However , the occurrence is sporadic... which makes it difficult to determine the source.

It seems like there is a niche somewhere in the plant that is harbouring the critter. There was a deep clean at the weekend so all being well it has been zapped.

The quest is being able to manage it without a listeriocidal step in the process.

[George @ Safefood 360°]

There has been a lot of research on this topic so I would suggest you spend some time reviewing the various scientific journals which will provide you with more informed scientific insight. There is no doubt that a Zero tolerance policy for Listeria has caused a lot of difficulty for food processing operations. In a raw shell fish operation the challanges are obvious.

Firstly the source may well be the raw product. Without a lethal step it is difficult to control this. If the source is environmental (process operation) then it is critical that you set up a good monitoring, management and action plan. This is a vast area for discussion and I will not attempt to go into it in this post. I would suggest you set about increasing your knowledge of the area first and then seek discussion on the finer detail.

Going back to my initial point, the following is a jourmal article which will help you get started.


Control of Listeria monocytogenes in the


A subscription to the digitial journals might be a good investment.

George.

[Charles.C]

Dear trubertq,

You unfortunately hv found a difficult customer. L.mono's claim to environmental ubiquity is extremely well-deserved IMEX, albeit often at a low level. For raw seafood, accepting a zero requirement (ie undetectable) order is in many cases akin to Russian Roulette IMO. Moreover I presume the product will be cooked later.

If not seen already can try this -

http://www.ifsqn.com...dpost__p__55872

Rgds / Charles.C

[trubertq]

Thanks George and Charles,

I have already read that article George, and also have found a good Listeria management programme from New Zealand.

The issue is that our customer doesn't want listeria in their plant ( for obvious reasons) and their customer doesn't want listeria in their plant.... so the responsibility is being put back onto the primary producer ( namely my client) to control the listeria, which I think is nigh on impossible without a kill step.

And all the many many articles I have read so far around this subject refer to RTE foods, I can't find specifics for a primary processed product. (RAW)

Edited by trubertq, 22 October 2012 - 04:20 PM.

[Charles.C]

Dear trubertq,

And all the many many articles I have read so far around this subject refer to RTE foods, I can't find specifics for a primary processed product. (RAW)

RTE documents may also contain raw-related data. Have another look at my previous post/link, attachment nn8, esp. section 5. This is a review up to ca. 2002 (The original source is –
 tt1 - L.mono smoked seafood working group 2002.pdf   281.83KB   6 downloads )

Some more recent treatment options / general situation assessments in this article –
http://www.foodsafet.../public/479.cfm

Slightly OT but I think it is at least 20yrs since the USFDA stopped controlling raw frozen shrimp imports for L.mono after dropping their original zero tolerance policy. (Became unrealistic after the species was accepted as a ubiquitous environmental contaminant.)

Also OT but I found this (Irish) quote / comment rather intriguing –

Studies in different food processing facilities across Europe over the past ten years have indicated that the principal source of L.monocytogenes contamination in foods prior to consumer purchase, preparation and consumption is the food processing environment(93. Research in Northern Ireland indicated that the incidence of L.monocytogenes in milk in processing facilities was up to six times higher (33.3%)than in samples of the same milk (5.3%)taken at the farm level(94-95) .

 tt2 - Control and Management of L.mono. Contamination of Food Ireland 2005.pdf   1.39MB   9 downloads

Rgds / Charles.C

PS - FWIW, this article on plant control options seemed quite nice pictorially speaking -
 tt3 - Controlling_Listeria.pdf   1.08MB   13 downloads

[trubertq]

Thanks Charles for the added information,

We think we have found our source and have exterminated it, for now. It has also provided me with a useful opportunity to stress the importance of GMP and Hygiene , and we have been doing some really good training sessions, where we are finding out about issues that had never had a forum before. The Company is expanding quickly and these are growing pains...


Tough lesson though

By the way , I have heard from a French customer that there is a 24hr rapid test for listeria, they don't understand why it takes us so long to get results. We outsource our listeria testing for obvious reasons ( we have enough trouble without listeria escaping into the plant), but I wonder if anyone here has used a rapid kit and if they are good enough to make a call on in the case of a recall ?

Our Food Safety Authority are hugely precautionary on these issues, and I suppose they are right if Ireland is going to promote itself as a place that produced good quality safe food..